1. Field of the Invention
The present invention relates to a functional substance including structured material containing a polymer, which can be used as various functional materials, a functional substance dispersed composition containing the structured material, and a liquid-applying process and apparatus for applying the composition.
2. Related Background Art
As for dispersed materials containing a functional substance, there have heretofore been well known agricultural chemicals such as herbicides and insecticides, medicaments such as anti-cancer drugs, anti-allergic drugs and antiphlogistics, and coloring materials containing a colorant as particulate solids, such as inks and toners. In recent years, among these, digital printing technology utilizing a composition containing a coloring material has been vigorously developed. Typical examples of this digital printing technology include those called electrophotographic technology and ink-jet technology, and its importance as image-forming technology in homes and offices has increased more and more in recent years.
Among these, the ink-jet technology has a great feature as a direct recording method in that it is compact and low in consumption power. The formation of high-quality images is also quickly advanced by formation of micro-nozzles or the like. An example of the ink-jet technology includes a method that an ink fed from an ink tank is evaporated and bubbled by heating it by a heater in a nozzle, thereby ejecting the ink to form an image on a recording medium. Another example includes a method that an ink is ejected from a nozzle by vibrating a piezoelectric element.
In order to improve weathering resistance and fixing ability, it is investigated to use pigment-dispersed inks as inks for ink-jet. U.S. Pat. No. 5,085,698 has proposed a method that a pigment is dispersed by an ionic block polymer having at least one hydrophilic component and at least one hydrophobic component. However, a further improvement is desired in point of inhibiting aggregation by interaction between particles to stably disperse the pigment in a solvent over a long period of time and from the viewpoints of tint, coloring ability and fixing ability.